Parentage assignment reveals multiple paternity in the critically-endangered Guatemalan beaded lizard (Heloderma charlesbogerti)

Within captive management programs for species of conservation concern, understanding the genetic mating system is of fundamental importance, given its role in generating and maintaining genetic diversity and promoting opportunities for sperm competition. If a goal of a conservation program is reintroduction, knowledge of the mating system may also inform prediction models aimed at understanding how genetic diversity may be spatially organized, thus informing decisions regarding where and which individuals should be released to maximize genetic diversity in the wild population. Within captive populations, such information may also influence how animals are maintained in order to promote natural behaviors. Here we investigate the genetic mating system of the Guatemalan beaded lizard, Heloderma charlesbogerti, a member of an entire clade lacking such information. A group of adult male and female H. charlesbogerti co-habited a large outdoor enclosure for five years during the species' perceived breeding season. Through genomic parentage analysis, 50% of clutches comprising multiple offspring were found to result from multiple paternity, with up to three males siring offspring within single clutches. Both males and females were observed to produce offspring with multiple partners within a given year. As such, within this captive environment, where opportunities existed for mating with multiple partners, the genetic mating system was found to be highly polygamous, with multiple paternity common within clutches. These findings are novel for the family Helodermatidae, and the results have broader implications about how reproductive opportunities should be managed within captive conservation programs.